AI 中文总结
本研究在光学实验中实现最小三节点UC网络，结合观测与干预数据的因果数据融合协议，观测到混合因果不等式被违背超三个标准差，为设备无关量子协议提供实验平台。
AI 中文摘要
量子因果网络可在放松部分物理上无根据假设的情况下，检验超越贝尔非定域性的非经典性。通过放松选择自由和类空间隔假设，无关混淆因子（unrelated-confounders, UC）因果网络为验证量子非经典性提供了简单且鲁棒的途径。本研究在光学实验中实现了最小三节点UC网络，使用两个独立的偏振纠缠光子源，并在中心节点处进行干预，该干预通过高保真纠缠测量实验完成。研究采用因果数据融合协议，结合观测数据与干预数据，显著提升了协议的噪声容忍度，实验中观测到相应混合因果不等式被违背超过三个标准差。研究结果为网络中的量子非定域性提供了更深入的见解，并凸显UC网络是一种紧凑、实验可实现的平台，可用于无需主动选择测量设置的设备无关量子协议。
英文摘要
Quantum causal networks enable tests of nonclassicality beyond Bell nonlocality while relaxing some physically unwarranted assumptions. By relaxing the freedom-of-choice and spacelike-separation assumptions, the unrelated-confounders causal networks provide a simple and robust route to certify quantum nonclassicality. Here, we implement the minimal three-node unrelated-confounders network in an optical experiment using two independent polarization-entangled photon sources and an intervention at the central node, experimentally achieved with a high-fidelity entangling measurement. We employ a causal data-fusion protocol that combines observational and interventional data to significantly improve the protocol's noise tolerance, and observe a violation of the corresponding hybrid causal inequality by more than three standard deviations. Our results provide deeper insights into quantum nonlocality in networks and highlight the UC network as a compact, experimentally accessible platform for device-independent quantum protocols that do not require actively chosen measurement settings.
